Xcode: Creating a Segue Connection programmatically for custom component - ios

I have created a custom uiscrollview and want an action on the uiscrollview to trigger a segue. I realise that all controls that trigger a segue have a "triggered segues" section in their connections inspector.
- (IBAction)startSegue....
In the .h file fits under the "Received Actions" section, is there a way to programmatically create a connection under the "triggered segues" connection to enable a custom class control to act as a connection for a segue?
Thanks
D

No, you can't do what you're suggesting. You need to make segue from the view controller, and call performSegueWithIdentifier:sender: inside one of the scroll view's delegate methods.

You can trigger a segue programatically if that is what you're asking. Create a method which is called after from action (a button or motion on the UIScrollView) and call a method similar to this: (Taken from Creating a segue programmatically)
-(void) someMethod{
MyNewViewController *myNewVC = [[MyNewViewController alloc] init];
// do any setup you need for myNewVC
[self presentModalViewController:myNewVC animated:YES];
}

Related

Xcode - Segue from UIImageView to new ViewController

Simple question that I'm currently having trouble as to how to get started.
I have a ViewController with multiple images/icons, and I would like to have new view controllers for each image/icon that is selected. I have a segue (show) from my initial view controller to my new one...but now how do I code it so when I click on a specific image it'll segue to the corresponding VC I want?
Thanks in advance!
If all of your Images/Links goes to one kind of ViewController, you can link it with segue in your interface builder and so you use just -performSegueWithIdentifier and seed it with your data or model corresponding to your ViewController.
For getting touch events and handling it, you can use delegate method which each subviews call their delegate when touch event catches. Assume below code for better imagination:
//Added in initiation of SubView
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGestureUpdated)];
//This function will be fired when gesture recognized
- (void)tapGestureUpdated {
if ([self.tapDelegate respondsToSelector:#selector(onItemTapped:)]) {
[self.tapDelegate onItemTapped:self.item];
}
}
But if you're showing to different types of ViewControllers, for each kind you should add segue and ViewControllers.
Superview will call next ViewController like this:
[self performSegueWithIdentifier:#"showNextViewControllerSegue" sender:self];
So there is such event chain for handling it:
UITapGestureRecognizer -> Your SubView -> Call it's delegate
(SuperView) -> Call next segue according to subView's type.

Access contained UIView component from Parent ViewController

In my parent viewcontroller, I have a view container, I added a subview to it:
m_cardDetail = [[CardDetailView alloc] init];
[_m_viewContainer addSubview:m_cardDetail];
[m_cardDetail initialize];
But how can I let my parent viewcontroller process a button click (button resides in m_cardDetail subview). I tried setting the button tag property of the button to 1010 and using this code in parent viewcontroller:
UIButton *aButtonView = (UIButton *)[m_cardDetail viewWithTag:1010];
[aButtonView addTarget:self action:#selector(aButtonTapped:) forControlEvent:UIControlEventTouchUpInside];
and also added this in viewcontroller:
- (void) aButtonTapped:(UIButton *) sender {
//Do something
}
but im getting the Unrecognized selector error
You should treat another view controller's views as private, even one that is a child view controller. As #Ostanik suggests in his answer (voted), setting up a protocol and a delegate is a good way to make a connection between a parent and child.
Note that an embed segue is a very clean way to set up the parent/child link. You simply create a container view in IB and control-drag from the container view to the scene of the view controller that you want to be a child, and Xcode does the rest. When the parent view controller is loaded the embed segue is invoked and you can set up the delegate in your prepareForSegue method.

ViewDidLoad not called on custom objects in Storyboard

I finally made the switch to Storyboards and i am having issues loading custom controllers which was pretty easy to do when using interface builder.
I have ViewControllerOne with two components: A UIView and UITableView as the subview.
I want the UITableView to be controlled by a custom tableview controller. If this was Interface builder i would have dropped a tableview controller onto the XIB, linked to the custom controller and made the connections and it would have been done.
Using storyboard, i don’t believe its possible to drop a UIViewController/UITableViewController onto a scene which already has a view controller, i relied on Objects to achieve this.
So i added a Object onto the scene and linked it to my custom tableview controller. I set up delegate/date source for my UITableView to point to the custom controller. I finally connected the UITableViews outlet to the custom controller.
When i compile this, the custom controllers delegate (for the table view) gets called but the viewDidLoad is never called.
The only way i can invoke viewDidLoad is if i move the UITableView out of ViewControllerOne. My understanding was that even though there is one view controller for a scene i can still manipulate the subviews using custom controllers.
Am i misunderstanding something or is there is a solution for this ?
Some screenshots
There is a bit of magic in that. Call self.view from awakeFromNib and flow will back to the rails
- (void)awakeFromNib
{
[super awakeFromNib];
// here comes the magic - call self.view and view will load as expected
NSLog(#"awakeFromNib %#", self.view)
}
you can call it from initWithNibName:bundle:
- (id)initWithNibName:(NSString*)nibNameOrNil bundle:(NSBundle*)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
NSLog(#"awakeFromNib %#", self.view);
}
return self;
}
the point is to call self.view because apparently something is done inside.
If I have understood your question correctly:
1 Open the storyboard and navigate to the table view controller that you would like to be of your custom type.
2 Click on the identity inspector in the right hand side panel.
3 Set the class to what it should be.

IOS: Stay on the first view controller before complete all controls (StoryBoard)

I connected first view controller with the second one using StoryBoard Push Segue and Interface Builder.
The button is named GO on top/right.
I have three textfield that must be filled before going to second controller.
I display an alert when one of them is empty.
The problem is that my code after displaying correct alertView goes to SecondController instead of remaining on mainController.
if ([segue.identifier isEqualToString:#"DataDisplay"])
{
if (![self verifySelection]) {
return;
} else {
RowViewController *rowViewController = segue.destinationViewController;
// rowViewController.delegate = self;
}
}
1) You have a segue wired directly from your Go button to your Sensor Data view controller. You don't want this, because anytime someone touches Go, the segue is going to happen ... no stopping it. So, first step is to remove the segue you have going from Go to your second view controller.
2) Instead, wire the segue from the File's Owner icon below the view controller to the second view controller. Give it a name like DataDisplay.
3) In the IBAction for your Go button
if ([self verifySelection) {
[self performSegueWithIdentifier:#"DataDisplay" sender:self]
}
An easy fix would be to create the segue manually, rather than letting the interface builder manage it. So you would ctrl-drag from your main view controller to your second one, selecting push as the type of segue and assigning it an identifier through the identifier inspector, then you connect an IBAction to your Go button and in the method you perform the checks on the text fields before programmatically firing the segue with:
[self performSegueWithIdentifier:#"whateverIdentifierYouGaveYourSegue" sender:self];
Heads up: to create a manual segue from a viewcontroller to another one, you need to either zoom out in your storyboard or ctrl-drag from the yellow circle underneath the view!
Edit: Your IBAction connected to the button method should be something like the following:
- (IBAction)download:(id)sender {
if(text boxes are ok)
[self performSegueWithIdentifier:#"segueIdentifier" sender:self];
else
[self showWarning];
}
Make sure that you assigned the ID segueIdentifier to the segue you created in your storyboard.
Your problem is you are defining the "performSegueWithIdentifier" after displaying the alert.
I think the code you are doing is like this :
//AlertView Allocation
[alert show];
Perform Segue
If this is how you are doing, then you are doing it wrong.
You have to use the structure of If-Else Statements and put up the Perform Segue in the condition where all the textfields are filled.

Creating a segue programmatically

I have a common UIViewController that all my UIViewsControllers extend to reuse some common operations.
I want to set up a segue on this "Common" UIViewController so that all the other UIViewControllers inherit.
I am trying to figure out how do I do that programmatically.
I guess that the question could also be how do I set a segue for all my UIViewControllers without going into the story board and do them by hand.
I thought I would add another possibility. One of the things you can do is you can connect two scenes in a storyboard using a segue that is not attached to an action, and then programmatically trigger the segue inside your view controller. The way you do this, is that you have to drag from the file's owner icon at the bottom of the storyboard scene that is the segueing scene, and right drag to the destination scene. I'll throw in an image to help explain.
A popup will show for "Manual Segue". I picked Push as the type. Tap on the little square and make sure you're in the attributes inspector. Give it an identifier which you will use to refer to it in code.
Ok, next I'm going to segue using a programmatic bar button item. In viewDidLoad or somewhere else I'll create a button item on the navigation bar with this code:
UIBarButtonItem *buttonizeButton = [[UIBarButtonItem alloc] initWithTitle:#"Buttonize"
style:UIBarButtonItemStyleDone
target:self
action:#selector(buttonizeButtonTap:)];
self.navigationItem.rightBarButtonItems = #[buttonizeButton];
Ok, notice that the selector is buttonizeButtonTap:. So write a void method for that button and within that method you will call the segue like this:
-(void)buttonizeButtonTap:(id)sender{
[self performSegueWithIdentifier:#"Associate" sender:sender];
}
The sender parameter is required to identify the button when prepareForSegue is called. prepareForSegue is the framework method where you will instantiate your scene and pass it whatever values it will need to do its work. Here's what my method looks like:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"Associate"])
{
TranslationQuizAssociateVC *translationQuizAssociateVC = [segue destinationViewController];
translationQuizAssociateVC.nodeID = self.nodeID; //--pass nodeID from ViewNodeViewController
translationQuizAssociateVC.contentID = self.contentID;
translationQuizAssociateVC.index = self.index;
translationQuizAssociateVC.content = self.content;
}
}
I tested it and it works.
By definition a segue can't really exist independently of a storyboard. It's even there in the name of the class: UIStoryboardSegue. You don't create segues programmatically - it is the storyboard runtime that creates them for you. You can normally call performSegueWithIdentifier: in your view controller's code, but this relies on having a segue already set up in the storyboard to reference.
What I think you are asking though is how you can create a method in your common view controller (base class) that will transition to a new view controller, and will be inherited by all derived classes. You could do this by creating a method like this one to your base class view controller:
- (IBAction)pushMyNewViewController
{
MyNewViewController *myNewVC = [[MyNewViewController alloc] init];
// do any setup you need for myNewVC
[self presentModalViewController:myNewVC animated:YES];
}
and then in your derived class, call that method when the appropriate button is clicked or table row is selected or whatever.
I've been using this code to instantiate my custom segue subclass and run it programmatically. It seems to work. Anything wrong with this? I'm puzzled, reading all the other answers saying it cannot be done.
UIViewController *toViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"OtherViewControllerId"];
MyCustomSegue *segue = [[MyCustomSegue alloc] initWithIdentifier:#"" source:self destination:toViewController];
[self prepareForSegue:segue sender:sender];
[segue perform];
Guess this is answered and accepted, but I just would like to add a few more details to it.
What I did to solve a problem where I would present a login-view as first screen and then wanted to segue to the application if login were correct. I created the segue from the login-view controller to the root view controller and gave it an identifier like "myidentifier".
Then after checking all login code if the login were correct I'd call
[self performSegueWithIdentifier: #"myidentifier" sender: self];
My biggest misunderstanding were that I tried to put the segue on a button and kind of interrupt the segue once it were found.
You have to link your code to the UIStoryboard that you're using. Make sure you go into YourViewController in your UIStoryboard, click on the border around it, and then set its identifier field to a NSString that you call in your code.
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard"
bundle:nil];
YourViewController *yourViewController =
(YourViewController *)
[storyboard instantiateViewControllerWithIdentifier:#"yourViewControllerID"];
[self.navigationController pushViewController:yourViewController animated:YES];
For controllers that are in the storyboard.
jhilgert00 is this what you were looking for?
-(IBAction)nav_goHome:(id)sender {
UIViewController *myController = [self.storyboard instantiateViewControllerWithIdentifier:#"HomeController"];
[self.navigationController pushViewController: myController animated:YES];
}
OR...
[self performSegueWithIdentifier:#"loginMainSegue" sender:self];
well , you can create and also can subclass the UIStoryBoardSegue . subclassing is mostly used for giving custom transition animation.
you can see video of wwdc 2011 introducing StoryBoard. its available in youtube also.
http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIStoryboardSegue_Class/Reference/Reference.html#//apple_ref/occ/cl/UIStoryboardSegue
I'd like to add a clarification...
A common misunderstanding, in fact one that I had for some time, is that a storyboard segue is triggered by the prepareForSegue:sender: method. It is not. A storyboard segue will perform, regardless of whether you have implemented a prepareForSegue:sender: method for that (departing from) view controller.
I learnt this from Paul Hegarty's excellent iTunesU lectures. My apologies but unfortunately cannot remember which lecture.
If you connect a segue between two view controllers in a storyboard, but do not implement a prepareForSegue:sender: method, the segue will still segue to the target view controller. It will however segue to that view controller unprepared.
Hope this helps.
Storyboard Segues are not to be created outside of the storyboard. You will need to wire it up, despite the drawbacks.
UIStoryboardSegue Reference clearly states:
You do not create segue objects directly. Instead, the storyboard
runtime creates them when it must perform a segue between two view
controllers. You can still initiate a segue programmatically using the
performSegueWithIdentifier:sender: method of UIViewController if you
want. You might do so to initiate a segue from a source that was added
programmatically and therefore not available in Interface Builder.
You can still programmatically tell the storyboard to present a view controller using a segue using presentModalViewController: or pushViewController:animated: calls, but you'll need a storyboard instance.
You can call UIStoryboards class method to get a named storyboard with bundle nil for the main bundle.
storyboardWithName:bundle:
First of, suppose you have two different views in storyboard, and you want to navigate from one screen to another, so follow this steps:
1). Define all your views with class file and also storyboard id in identity inspector.
2). Make sure you add a navigation controller to the first view. Select it in the Storyboard and then Editor >Embed In > Navigation Controller
3). In your first class, import the "secondClass.h"
#import "ViewController.h
#import "secondController.h"
4). Add this command in the IBAction that has to perform the segue
secondController *next=[self.storyboard instantiateViewControllerWithIdentifier:#"second"];
[self.navigationController pushViewController:next animated:YES];
5). #"second" is secondview controller class, storyboard id.
I reverse-engineered and made an open source (re)implementation of UIStoryboard's segues: https://github.com/acoomans/Segway
With that library, you can define segues programmatically (without any storyboard).
Hope it may help.
A couple of problems, actually:
First, in that project you uploaded for us, the segue does not bear the "segue1" identifier:
no identifier
You should fill in that identifier if you haven't already.
Second, as you're pushing from table view to table view, you're calling initWithNibName to create a view controller. You really want to use instantiateViewControllerWithIdentifier.
Here is the code sample for Creating a segue programmatically:
class ViewController: UIViewController {
...
// 1. Define the Segue
private var commonSegue: UIStoryboardSegue!
...
override func viewDidLoad() {
...
// 2. Initialize the Segue
self.commonSegue = UIStoryboardSegue(identifier: "CommonSegue", source: ..., destination: ...) {
self.commonSegue.source.showDetailViewController(self.commonSegue.destination, sender: self)
}
...
}
...
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// 4. Prepare to perform the Segue
if self.commonSegue == segue {
...
}
...
}
...
func actionFunction() {
// 3. Perform the Segue
self.prepare(for: self.commonSegue, sender: self)
self.commonSegue.perform()
}
...
}

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